package com.androidcat.jly.utils;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.SharedPreferences;
import android.provider.Settings.Secure;
import android.telephony.TelephonyManager;
import android.text.TextUtils;

import java.io.UnsupportedEncodingException;
import java.util.UUID;

public class DeviceUuidFactory {
  protected static final String PREFS_FILE = "device_id.xml";
  protected static final String PREFS_DEVICE_ID = "device_id";
  protected static UUID uuid;
  private static DeviceUuidFactory deviceUuidFactory;

  public static DeviceUuidFactory obj(Context context){
    if (deviceUuidFactory == null) deviceUuidFactory = new DeviceUuidFactory(context);
    return deviceUuidFactory;
  }

  @SuppressLint("MissingPermission")
  private DeviceUuidFactory(Context context) {
    if( uuid ==null ) {
      synchronized (DeviceUuidFactory.class) {
        if( uuid == null) {
          final SharedPreferences prefs = context.getSharedPreferences( PREFS_FILE, Context.MODE_PRIVATE);
          final String id = prefs.getString(PREFS_DEVICE_ID, null );
          if (id != null) {
            // Use the ids previously computed and stored in the prefs file
            uuid = UUID.fromString(id);
          } else {
            final String androidId = Secure.getString(context.getContentResolver(), Secure.ANDROID_ID);
            // Use the Android ID unless it's broken, in which case fallback on deviceId,
            // unless it's not available, then fallback on a random number which we store
            // to a prefs file
            try {
              if (!"9774d56d682e549c".equals(androidId)) {
                uuid = UUID.nameUUIDFromBytes(androidId.getBytes("utf8"));
              } else {
                TelephonyManager tm = ((TelephonyManager) context.getSystemService( Context.TELEPHONY_SERVICE ));
                String deviceId = tm.getDeviceId();
                if (TextUtils.isEmpty(deviceId)){
                  //序列号（sn）
                  deviceId = tm.getSimSerialNumber();
                }
                uuid = deviceId!=null ? UUID.nameUUIDFromBytes(deviceId.getBytes("utf8")) : UUID.randomUUID();
              }
            } catch (UnsupportedEncodingException e) {
              //throw new RuntimeException(e);
              uuid = UUID.randomUUID();
            }
            // Write the value out to the prefs file
            prefs.edit().putString(PREFS_DEVICE_ID, uuid.toString() ).commit();
          }
        }
      }
    }
  }
  /**
   * Returns a unique UUID for the current android device.  As with all UUIDs, this unique ID is "very highly likely"
   * to be unique across all Android devices.  Much more so than ANDROID_ID is.
   *
   * The UUID is generated by using ANDROID_ID as the base key if appropriate, falling back on
   * TelephonyManager.getDeviceID() if ANDROID_ID is known to be incorrect, and finally falling back
   * on a random UUID that's persisted to SharedPreferences if getDeviceID() does not return a
   * usable value.
   *
   * In some rare circumstances, this ID may change.  In particular, if the device is factory reset a new device ID
   * may be generated.  In addition, if a user upgrades their phone from certain buggy implementations of Android 2.2
   * to a newer, non-buggy version of Android, the device ID may change.  Or, if a user uninstalls your app on
   * a device that has neither a proper Android ID nor a Device ID, this ID may change on reinstallation.
   *
   * Note that if the code falls back on using TelephonyManager.getDeviceId(), the resulting ID will NOT
   * change after a factory reset.  Something to be aware of.
   *
   * Works around a bug in Android 2.2 for many devices when using ANDROID_ID directly.
   *
   * see doc http://code.google.com/p/android/issues/detail?id=10603
   *
   * @return a UUID that may be used to uniquely identify your device for most purposes.
   */
  public static UUID getDeviceUuid() {
    //return UUID.fromString("db5210fa-5afd-36d6-a586-353d0c48b6f1");
    return uuid;
  }
}
